Biomedical subjects

J Chakraborty

Publications and source records attributed to J Chakraborty.

At least 55 records · Page 3Linked to original sources

PubMed1994

Identification of a mucin layer in the urinary bladder.

OBJECTIVES: The specific goal of this study was to establish a simple histochemical technique by which the glycosaminoglycan (GAG) lining in the rabbit bladder can be routinely identified. METHODS: Rabbit bladder tissues were fixed in zinc formal, 10% neutral buffered formalin (NBF), 20% NBF, 40% NBF, 2% calcium acetate in 10% NBF, 2% sodium acetate in 10% NBF, 1% cetylpyridinium chloride in 10% NBF, 80% alcohol, histochoice, and 2.5% glutaraldehyde in 0.1 M cacodylate buffer. The following histochemical staining was used: mucicarmine/metanil yellow, colloidal iron, deamination followed by colloidal iron, periodic acid-Schiff, saponification followed by colloidal iron, Alcian blue (AB) at variable pH values, combined aldehyde-fuchsin/AB, performic acid/AB, AB/Alcian yellow, high temperature (60 degrees C) methylation/saponification/AB, and AB/nuclear fast red at pH 5.8 with critical electrolyte concentrations with or without deamination. RESULTS: AB with sodium acetate buffer at pH 5.8 containing 0.6 M or 0.8 M magnesium chloride (MgCl2) showed a well-defined thin GAG lining on the surface of the urothelium, whereas histochemical staining used by previous investigators showed only patchy distribution. There was no observable difference due to the gender, fixative, or region of the bladder from which the tissue was obtained. CONCLUSIONS: A very thin lining of GAG exists in the rabbit bladder which can be localized by AB in sodium acetate buffer at pH 5.8 containing 0.6 M or 0.8 M MgCl2 but not by conventional histochemical techniques. This method now can be applied to answer many questions regarding urothelial function.

Alcian Blue↗

PubMed1994

The effects of dietary sugar-beet fibre and guar gum on lipid metabolism in Wistar rats.

This study investigates the mechanisms of action for the hypocholesterolaemic effects of sugar-beet fibre (SBF) and guar gum. Four groups of ten male Wistar rats were fed ad lib. on test diets containing either 100 g SBF or guar/kg, or control diets containing 100 g cellulose or wheat bran/kg for 28 d. Food intake, weight gain and food consumption ratios were unaffected by the diets. Circulating cholesterol and hepatic cholesterol concentrations were significantly lower in both SBF- and guar-fed groups compared with either cellulose- or bran-fed animals. Circulating triacylglycerol concentrations were significantly lower in SBF- and guar-fed animals, but total hepatic lipid concentrations and hepatic and adipose tissue lipogenesis rates were unaffected by the diets. Hepatic cholesterol-7 alpha-hydroxylase (EC 1.14.13.17) activities were significantly higher in the guar-fed animals compared with cellulose or bran control groups. Hepatic 3-hydroxy-3-methylglutaryl-CoA reductase (EC 1.1.1.88) activities were unaffected. Circulating bile acid concentrations were significantly lower in SBF- and guar-fed animals and faecal bile acid output was significantly higher in the guar-fed group compared with bran- or cellulose-fed groups. This study supports the hypothesis that guar exerts its hypocholesterolaemic effect via intraluminal bile acid binding and loss of cholesterol from increased faecal bile acid excretion. The mechanism of action for the hypocholesterolaemic effect of SBF is less clear; the results of the present study point to a mechanism involving disruption of the enterohepatic bile acid circulation, possibly via changes in the rate of absorption of dietary lipid.

Adipose Tissue↗

PubMed1994

Acute respiratory infections (ARI) in rural Bangladesh: perceptions and practices.

Acute Respiratory Infections (ARI) are a major cause of death in children under five in rural Bangladesh. A popular strategy for lowering ARI mortality in such settings includes detecting and managing pneumonia in children at the community level. The success of programs using this approach requires a well-trained community-based cadre of health workers and the appropriate utilization of services provided. Determinants of health care seeking behavior are clearly of interest in this regard. A qualitative study was conducted in Matlab, Bangladesh to describe community perceptions of signs and symptoms of ARI, case management behavior, and constraints to service utilization. Mothers recognized pneumonia and thought it to be caused by "exposure to cold." They were able to identify labored breathing, chest retractions, lethargy, and inability to feed as signs of severe disease needing treatment outside the home. Nevertheless, similar illnesses were sometimes believed to be due to attack by evil influences. In these cases, spiritual healers were sought and allopathic treatment was avoided or delayed. The mothers' observance of purdah and "proper" behavior were reported to play a role in prevention of child death from disease. Implications of this belief and its impact on service utilization are discussed. Suggestions for program managers are made in addition to recommendations for further research.

Acute Disease↗

PubMed1994

Measles in rural Bangladesh: issues of validation and age distribution.

In the Third World, scientists have described thoroughly the pattern of measles in Africa. In Asia, however, the epidemiology of measles has been poorly described. In 1989, a measles surveillance system was initiated in Matlab, rural Bangladesh in order to monitor measles incidence in the area. The population (100,000), which has relatively low immunization coverage, has an excellent demographic surveillance system which allows accurate follow-up. The system works through trained community health workers who visit all households every fortnight and report possible cases of measles. Medical doctors review a proportion of index cases and cases in infants soon after the appearance of the rash. Of the 4673 cases reported in all age groups, 18% were visited by medics. Confirmation of diagnosis was related to the age at onset and overreporting by community health workers is documented. The incidence of measles was estimated at 43% of children < 5 years old. Of cases < 5 years of age, 14% occurred below the age at vaccination (incidence rate = 5.5%). A strong seasonal pattern is reported. Case-fatality rates are low. This is the first report which shows the effect of age on reliability of reported measles. It shows the misclassification likely to occur when reporting measles in large-scale surveys, particularly in infants. It also shows that the pattern of measles in this community resembles the pattern reported for African communities and calls for a review of immunization strategies with vaccination below 9 months of age.

Age Factors↗

PubMed1993

Acute toxicity of vitamin A given with vaccines in infancy.

A double-blind, randomised, placebo-controlled trial was conducted to evaluate the safety and toxicity of vitamin A supplementation within the Expanded Programme on Immunisation (EPI) in rural Bangladesh. 191 infants received 3 doses of either 50,000 IU of vitamin A or placebo at about 1.5, 2.5, and 3.5 months and were examined on days 1, 2, 3, and 8 after supplementation. 11 infants (11.5%) supplemented with vitamin A had episodes of bulging of the fontanelle as opposed to 1 (1%) in the placebo group. 16 of the 17 events occurred in the vitamin A supplemented group. No other side effects were noted. There was a tendency towards a cumulative effect of toxicity with increasing doses.

Bangladesh↗

PubMed1993

Effects of cocaine on fetal and postnatal development in mice.

The goal of the current investigation was to study the effect of in utero exposure of cocaine on fetal and postnatal development. 48 adult female NIH Swiss mice were used as experimental animal models. Each of the 24 mice were injected intraperitoneally with cocaine HCl at a daily dose level of 45 mg/kg (body weight). Each of the 24 control animals were daily injected with saline. One week after the treatment started, one male was introduced into each female cage. The day the vaginal plug was found was recorded as day one of pregnancy. Both cocaine treated and saline treated animals were subdivided into three subgroups each with 8 animals in each subgroup. Subgroup one was used to obtain midgestational (11 day) fetuses, subgroup two was used to obtain full term fetuses (18 day) and subgroup three was used to obtain pups. Individual fetal weights were taken and each fetus was examined for developmental anomalies. Midgestational fetuses exposed to cocaine had lower body weights than those of the controls. The full term fetuses, however, had similar weight in both experimental and control groups. The pups were weighed every 2 days from day 2 to day 16. The pups showed a slightly wider range of weights in the cocaine treated group as they matured to 16 days. All fetuses and pups revealed no soft tissue anomaly which, along with the weight data, supported our earlier findings.

Aging↗

PubMed1993

Gender and age differentials in risk factors for childhood malnutrition in Bangladesh.

A case-control study of risk factors of clinical marasmus was undertaken to determine which factors differed according to gender and age groups. Case patients were children whose mid-upper arm circumference measured less than 110 mm and control subjects were children matched for age and sex with an arm circumference more than 120 mm. Between June 1988 and June 1989, 164 such pairs of children aged 1 to 4 years were studied. The effect of various demographic, socioeconomic, environmental, and health factors was investigated in a multivariate analysis using conditional logistic regression. Results showed an increased risk of marasmus among children with siblings under 5 years old. This increased risk was observed irrespective of gender or age. Children who consumed formula foods also had an increased risk of marasmus. Again, this elevated risk was maintained for boys and girls. Overall, higher maternal education was associated with a reduced risk of marasmus; however, this was only statistically significant for boys and for children 18 months or older. Religion was also associated with marasmus but only in older children (> or = 18 months). These results indicate that better strategic planning is necessary to formulate effective interventions to reduce severe malnutrition, particularly in societies where strong age- and sex-preferential behavior exists.

Age Factors↗

PubMed1993

Risk factors for clinical marasmus: a case-control study of Bangladeshi children.

A case-control study of risk factors of clinical marasmus was undertaken to guide intervention efforts in rural Bangladesh. Cases were children whose mid-upper arm circumference measured < 110 mm and controls were children matched for age and sex with arm circumference > 120 mm. Between June 1988 and June 1989, 164 such pairs of children aged 1-4 years were studied. The effects of various demographic, socioeconomic, environmental, and health factors, reported by mothers, were investigated in a multivariate analysis using conditional logistic regression. Results showed an increased risk of marasmus among children from families with other children under 5 years of age (odds ratio [OR] = 2.51; 95% confidence interval [CI]: 1.33-4.74), and children who consumed formula foods (OR = 16.41, 95% CI: 3.39-79.36). Higher maternal education was associated with reduced risk of marasmus, compared with no education, the OR for < 5 years of schooling = 0.57, 95% CI: 0.23-1.41; OR for > or = 5 years of schooling = 0.34, 95% CI: 0.15-0.76. The strong association of childhood marasmus with mother's education and child spacing supports the notion that non-nutritional factors should be essential components of efforts to reduce severe malnutrition in Bangladesh.

Bangladesh↗

PubMed1993

The design and analysis of cholera vaccine trials: recent lessons from Bangladesh.

The recent spread of cholera to Latin America, together with the persistent burden of this disease in Asia and Africa, have stimulated efforts to evaluate new cholera vaccines in field settings. Although the standard experimental paradigm for vaccine field trials is well established, the success of these trials will also depend on suitable consideration of the epidemiology of cholera and of cholera vaccination in the setting under study. Epidemiological studies done in Bangladesh emphasize the importance of appreciating the poorly predictable, multifocal occurrence of cholera in estimating a probable incidence of cholera for a field trial. They also underscore how the filtering effect of enrolling subjects into a prospective trial can dramatically reduce the available population for study, and can yield a study sample whose expected risk of cholera differs markedly from that for the source population. Finally, the data highlight the subtle effects that the mode of surveillance and the choice of an outcome definition can have upon protective efficacy, and emphasize the need for subgroup analyses that address the distinctive variations in vaccine protection that may occur in subjects differing in age and in ABO blood groups, and in subjects exposed to classical versus El Tor cholera.

ABO Blood-Group System↗

PubMed1993

Breast-feeding and the risk of life-threatening rotavirus diarrhea: prevention or postponement?

PURPOSE: To assess the relationship between breast-feeding and the risk of life-threatening rotavirus diarrhea among Bangladeshi infants and children younger than 24 months of age. DESIGN: Case-control study. SETTING: A rural Bangladesh community. PARTICIPANTS: One hundred two cases with clinically severe rotavirus diarrhea detected in a treatment center-based surveillance system during 1985 and 1986, and 2587 controls selected in three surveys of the same community during the same calendar interval. OUTCOMES: Cases and controls were compared for the frequency of antecedent breast-feeding patterns. RESULTS: Compared with other feeding modes, exclusive breast-feeding of infants was associated with significant protection against severe rotavirus diarrhea (relative risk (RR) = 0.10; 95% confidence interval [CI] = 0.03, 0.34). However, during the second year of life, the risk of this outcome was higher in breast-fed than in non-breast-fed children (RR = 2.85; 95% CI = 0.37, 21.71), and no overall protection was associated with breast-feeding during the first 2 years of life (RR = 2.61; 95% CI = 0.62, 11.02). CONCLUSIONS: Although exclusive breast-feeding appeared to protect infants against severe rotavirus diarrhea, breast-feeding per se conferred no overall protection during the first 2 years of life, suggesting that breast-feeding temporarily postponed rather than prevented this outcome. While not detracting from efforts to promote breast-feeding to alleviate the burden of diarrhea due to nonrotaviral enteropathogens, our findings cast doubt on whether such efforts will impact on the problem of severe rotavirus diarrhea.

Bangladesh↗

PubMed1992

The risk approach to intervention in severe malnutrition in rural Bangladesh.

To determine whether clinical marasmus occurs in small groups of children from easily recognizable high-risk households, the authors conducted a case-control study to identify risk indicators that may be used in targeted interventions. Cases were children whose mid-upper arm circumference measured less than 110 mm, and controls were children matched for age and sex with arm circumferences greater than 120 mm. Between June 1988 and June 1989, 164 such pairs of children aged 1-4 years were studied in Matlab, Bangladesh. Conditional logistic regression analysis showed an increased risk of marasmus among children from families with other children under 5 years of age (odds ratio = 2.80, 95% confidence interval 1.56-5.02) and children who consumed formula foods (odds ratio = 18.81, 95% confidence interval 4.15-85). Higher maternal education was associated with reduced risk of marasmus. Further examination of these risk indicators suggests that the resources saved through targeting fewer households will be negated by missing many children with marasmus. The authors conclude that the application of targeted interventions against marasmus, using the risk approach, is unlikely to be efficient.

Arm↗

PubMed1992

Nonparticipation as a determinant of adverse health outcomes in a field trial of oral cholera vaccines.

The authors estimated the incidence rates of cholera and death between 1985 and 1988 for 32,642 age- and sex-eligible persons who did not participate in a randomized, placebo-controlled field trial of killed oral cholera vaccines in rural Bangladesh. As compared with 20,744 placebo recipients, the relative risk of cholera for all nonparticipants, adjusted for potentially confounding demographic variables, was 1.20 (95% confidence interval (CI) 1.03-1.41); this adjusted relative risk reflected elevated adjusted relative risks in nonparticipants who were medically ineligible (RR = 1.65; 95% CI 1.22-2.22) or refused to participate (RR = 1.19; 95% CI 1.01-1.41), but not in persons absent at the time of vaccination (RR = 1.00; 95% CI 0.78-1.28). The adjusted relative risk of death was also elevated in nonparticipants as compared with placebo recipients (RR = 1.28; 95% CI 1.10-1.48), with the same pattern of adjusted relative risks for different categories of nonparticipants: for ineligible subjects, 2.64 (95% CI 2.12-3.29); for refusers, 1.20 (95% CI 1.02-1.41); and for absentees, 0.95 (95% CI 0.75-1.22). The authors concluded that nonparticipation was associated with clinically cogent adverse health outcomes, but that the magnitude of these associations varied according to the reason for nonparticipation. These findings underscore the caution required in assessing vaccine efficacy with controls who are not vaccinated because of choices made by patients or vaccinators.

Administration, Oral↗

PubMed1992

Antioxidant defenses in the bile duct-ligated rat.

Changes in pro-oxidant and antioxidant balance in the serum and liver were studied in an experimental model of obstructive jaundice in the rat. The results showed a decrease in plasma vitamin E concentration (P < 0.01) and a threefold reduction in liver vitamin E concentration (P < 0.001). There was also a threefold reduction in levels of the liver enzymes glutathione peroxidase (P < 0.01) and glutathione transferase (P < 0.001), together with a six-fold reduction in catalase activity (P < 0.001). The serum selenium level decreased by 35% in the jaundiced rats (P < 0.05). The total liver glutathione level decreased to half the control value (P < 0.01). The malonyldialdehyde level, the measure of lipid peroxidation used in this study, doubled (P < 0.01). The results suggest a shift in the pro-oxidant/antioxidant balance in favor of lipid peroxidation. The possible etiology of this change and its relationship to human cholestasis are discussed.

Animals↗

PubMed1992

Antimicrobial resistance of Shigella isolates in Bangladesh, 1983-1990: increasing frequency of strains multiply resistant to ampicillin, trimethoprim-sulfamethoxazole, and nalidixic acid.

The susceptibility to ampicillin and trimethoprim-sulfamethoxazole (TMP-SMZ) was determined for 15,824 isolates of Shigella obtained from patients attending a treatment center in Dhaka, Bangladesh, from 1983 through 1990 and for 520 isolates obtained during community surveys from 1988 through 1990. Susceptibility to nalidixic acid was determined for isolates obtained after 1985. In 1983 13% of isolates were resistant to ampicillin, 23.5% to TMP-SMZ, and 0.8% to both drugs. By 1990 51.2% of isolates obtained at the Diarrhea Treatment Centre were resistant to ampicillin, 47.7% to TMP-SMZ, and 40.5% to both drugs (for comparison with figures for 1983, P less than .001). Resistance to nalidixic acid increased from 0.8% in 1986 to 20.2% in 1990 (P less than .001). In 1990 71.5% of Shigella dysenteriae type 1 isolates were resistant to ampicillin, 68.5% to TMP-SMZ, 67.7% to both drugs, and 57.9% to nalidixic acid. The resistance pattern of isolates obtained during community surveillance was similar to that of Treatment Centre isolates. In Bangladesh ampicillin and TMP-SMZ are no longer useful for treatment of infection with any species of Shigella, and nalidixic acid is no longer useful for treatment of infections due to S. dysenteriae type 1.

Ampicillin Resistance↗

PubMed1992

Evidence that inactivated oral cholera vaccines both prevent and mitigate Vibrio cholerae O1 infections in a cholera-endemic area.

In a randomized, placebo-controlled field trial of B subunit-killed whole cell (BS-WC) and killed whole cell only (WC) inactivated oral cholera vaccines in rural Bangladesh, active surveillance of selected neighborhoods during the first year after vaccination identified 127 Vibrio cholerae O1 infections among 3285 three-dose recipients. For each vaccine, protective efficacy was greater against symptomatic (57%, P < .05 for BS-WC; 58%, P < .05 for WC) than against asymptomatic infections (46%, P < .05 for BS-WC; 32%, P = .09 for WC), and protection against each grade of infection was demonstrable for both the classical and El Tor biotypes. Although vaccine protection against symptomatic infections was evident in both young children and older persons, only persons vaccinated at age > 5 years were protected against asymptomatic infections. These results suggest that the inactivated oral vaccines acted both to protect against intestinal colonization by V. cholerae O1 and to interrupt the pathogenic sequence of established infections.

Adolescent↗

PubMed1992

Methylprednisolone hemisuccinate and metabolites in urine from patients receiving high-dose corticosteroid therapy.

A reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the measurement of methylprednisolone hemisuccinate (MPHS) and its metabolites methylprednisolone (MP), 20-alpha- (20a-HMP), and 20-beta-hydroxymethylprednisolone (20b-HMP) in urine is described. The metabolites were extracted from urine samples using Extrelut columns and eluted with ethylacetate. The mobile phase for RP-HPLC comprised methanol:citrate buffer:tetrahydrofuran (30:65:5, vol/vol/vol) with UV detection at 251 nm. Fractions were collected, pooled and the metabolites present were identified by gas chromatography-mass spectrometry and normal-phase HPLC (NP-HPLC). By RP-HPLC 30 +/- 7.3% (mean +/- 1 SD) of the dose was detected in the 0-24 h urine sample following a 1 g MPHS infusion to patients with rheumatoid arthritis; MPHS contributed 9.9 +/- 5.0%, MP 12.1 +/- 2.9%, 20a-HMP 7.8 +/- 2.2%, and 20b-HMP 1.0 +/- 0.3%, respectively. A further 1.0 +/- 0.9% of the administered dose was detected in urine collected 24-48 h postinfusion.

Arthritis, Rheumatoid↗

PubMed1992

Persistent diarrhea as a cause of childhood mortality in rural Bangladesh.

To determine the importance of persistent diarrhea in childhood mortality a multiple-step verbal autopsy method was used to study 1934 deaths in Matlab, Bangladesh. We found that most of the deaths from acute watery diarrhea occurred in infancy, whereas the peak of non-watery diarrhea deaths was in children over 12 months of age. Children suffering from persistent diarrhea and malnutrition were at highest risk of dying during their third year of life. Children with infectious diseases have a two to four times higher risk of dying if they are malnourished, and for diarrhea the risk is 17 times as high. Forty-nine percent of the diarrheal deaths were in children with malnutrition associated with persistent diarrhea. These results imply that fluid and dietary management are key aspects in the treatment of diarrhea, particularly for those episodes which persist. We conclude that attempts to reduce diarrhoeal deaths with vertical ORT programmes will not have major impact unless other interventions are directed to the persistent diarrhoea-malnutrition complex.

Acute Disease↗

PubMed1992

Impact on mortality of a community-based programme to control acute lower respiratory tract infections.

Acute lower respiratory tract infections (ALRIs) are a major cause of death among young children in developing countries. A targeted programme designed to treat children with ALRI was implemented in 1988 in a primary health care project in rural Bangladesh. In the 2 years preceding the introduction of the programme (1986-87), non-ALRI-specific health services were provided, including promotion of oral rehydration therapy, family planning, immunization of children and mothers, distribution of vitamin A, referral of severely sick children to field clinics, and nutritional rehabilitation of malnourished children. The targeted ALRI programme, which was in place in 1988-89, was based on systematic ALRI case detection and management by community health workers, who were linked to a referral system for medical support. These two levels of intervention have been evaluated by comparing the ALRI-specific mortality in the programme area and a neighbouring control area during the two periods. During the first phase (1986-87), the ALRI mortality among under-5-year-olds was 28% lower in the intervention than in the comparison area (P less than 0.01). During the second phase (1988-89), the ALRI mortality was 32% lower in the intervention area than during the preceding phase, while there was no significant difference for the comparison area. These findings suggest that in the study region the combination of specific and nonspecific interventions can reduce ALRI mortality by as much as 50% and the overall mortality among under-5-year-olds by as much as 30%.

Allied Health Personnel↗